package day1;

/**
 * @author oldliu
 * @since 1.0
 */
public class StrTest {
    //不变性
    //常量池
    public static void main(String[] args) {
        byte[]b={65,66,67,97,98,99};
        String str=new String(b);
        System.out.println(str);
        String s4=str;
        str=str.concat(",java");
        //+
        str=str.toUpperCase();//全大写
        System.out.println(str);
        System.out.println("s4:"+s4);
    }
}
